BOB HIRSHON (host):
Human metabolic equality. I’m Bob Hirshon and this is Science Update.
The Hadza people of northern Tanzania live as rugged hunter-gatherers. Yet they burn about the same number of daily calories as Americans with desk jobs. This according to Hunter College biological anthropologist Herman Pontzer. His team wanted to learn about the metabolism of our prehistoric ancestors, and chose the Hadza as a model.
HERMAN PONTZER (Hunter College):
Based on other people’s estimates, we expected – we had no reason not to – that the Hadza would be burning many more calories a day than you and I do, so we were very surprised to see the result.
To explain it, he notes that most of our daily calories go toward basic cellular functions, not physical activity. And when we do increase our activity, our bodies adjust by spending fewer calories elsewhere. The findings suggest that exercise may not affect obesity as much as we thought, although Pontzer stresses that it’s still essential for overall health. I’m Bob Hirshon for AAAS, the Science Society.